Automobile headlamp



T. M BRAGG ET AL AUTOMOBILE HEDLAMP Oct. 21, 1924.. 1,512,158

Filed Fe 26 1924 2 Sheets-Sht 1 T. M. BRAGG ET AL AUTOMOBILE HEADLAMP Filed Feb. 26 1924 2 Sheets-Shest2 Il. 32 V i Patented Qct. 2.1, 1924.

UNITED STATES PATENT OFFICE.

TIIOMAS MILTON BRAGG, MUNGERIBAR, AND JOHN FREDERICK HOWARTH, OIE

MARRICKVILLE, NEAR SYDNEY, NEW SOUTII TALES, AUSTRALIA.

AUTOMOBILE HEADLAMP.

Application fi1ed February 26, 1924. Serial No. 695,188.

T 0 all w7wm 7325 mag cancan:

Be it known that we, THOMAS MILTON BRAGG and JOHN FREDERGK IIOWARTH, subjects of the King of Great Britain and reland, residing, respectively, at lWlungeribar, in the county of N arromine, State of New South Wales, A.ustralia, and 105 Fraser Street, Marrickville, near Sydney, in the county of Cumberland, State of New Smith 10 VVales, Australia, have invented certain new and useful Improvements in Automobile Headlamps, of which the following is a speoification.

The object of this invention is to provide an elective means whereby the driver of an automobile Will be enabled to vary the adjustment of the head lampe at Will, so as to minimize laIe efiect When approaching or passing ot1er trafiic, or When the car is standing. It is well recognized that the dimming of automobile head lamps is an objectionable practice inzismuch as the sudden change in the illumination discommodes the driver ofthe car, whose eyes being habit uated to observing the road ahead under full light conditions are incapable of immediatel v readjusting themselves to take a safe view of the road when the lamps are suddenly dimmed. Whilst, therefore, the dimming of lamps of a vehicle conveniences other drivers, such dimming is a source of danger to the driver of the vehicle itself;

According to the present invention, the full illumination of the hezid lampe is maintained, but the light source is temporarily defocussed at the W111 et the driver so that the glare effect resulting from a concentrated beam is destroyed and the light is diffused. An adequate condition of illumination is thus maintained always on the road immediately ahead of the car. Driving et normal speed can therefore be con tinued with safety, whilst the drivers of ap proaching vehicles are not discommoded as l1ey frequently are When a parallel concentrated beam of light is projected from the lampa Tlie burner of the lamp in the case of an oil or gas lamp, or the lamp itself in the case of an electric lamp, is mounted in relation to the refiector so thatthe light source islocated normally in the focus of the refiector with the object of producing a more or less parallel concentrated beam adapted for illuminating the 1Qfild QF a s1.1bstantial diS= tance in advance of the car. This normal adjustment is made variable by providing a means whereby the burneror the lamp, as the case may be, may be moved out et the refiector focus temporarily and so held as long as may be required, so as thereby to bring the source of light to a point more or less distant from the focal centre of the refiector. lVhen the source -of light 1's thus de-foeussed, a concentrated beam is no longer produced, dilused illumination only being produced. This illumination is ample for making the road surface immediately in front of the car olear to the driver, and as the light value apparent to the driver is maintained, the drivers vision is not substantially affected, so that he is always able to obtain a safe vievv 01: the road ahead.

The preferred arrangement for efiecting the de-focussing control is electromagnetic, and the driver is enabled by button or svvitch control to efiect the necessary movement of the lamp burner, or in the case of an electrio lamp the necessary movement of the lamp itself.

In the electromagnetic arrangement, tvvo electromagnets in opposed relation and a control magnet are used, with an armature movable obediently to the action of the magnets, but controlled as to the range of its movement by a check mechanism operated by the control magnet. The utility of the control magnet is to check the armature movement at an intermediate point vvhen it is desired by the driver t0 efi"ect only a partial de-focussing of the lamps. The armature movements are communicated through a short flexible shaft to a pinion Which ongages a raok on a long socket which carries an electric bulb, or, in the case of an oil lamp or a gas lamp, carries the burner et the lamp by a suitable attachment on its fore end. This socket is slidable in a sleeve which is slidable axially in a guide tube which is fixed to the back 01 the lamp refiectbr, and it is armed on one side oi it with toothed raclz The'socket projects io1 wardly through an aperture in the refiector. Normal focussing is efiected by means of a screw and bufier spring, the serew head being accessible at or through the back otthe lamp casing. The lamp is brought 1nto focus by adjusting the screw, thereby to 'move the sleeve to bring tl 1e socket to the correct position in 1elation to the fo cue 1.

the reflector, and the de-fcussihg is ob tained by moving thesocket out of tlns adjusted position forwardly or backwardly.

'Ei 5 is,a dia rammatib viewex. lanator D 23 Of the electric circuit and switch arrange.-

ment 7 Fig; 6? is a. fragmentary vrerw of: the check finger on. the armature ofthe control mag-' net..

Fig. 7 is a view of the armature in. position in its l1ousing;

' Fig; 8' is a vertical sectional view on line 88. of Fig. 7

Fig.. 9* is an el"evation, partl-y in section, 0:1 tlie control magnet;

Fig; 10 is a side. elevation 01 the control magnet;

Fig; 11. is a plan view of* the control magnet assembly;

Figs. 12, 13" and 14: are detail views of the check finger shown in relation to the check pin and Fig. 15 is an. inverted view partly in section, et the operatingelectromagnetso1ilino 10 is the lamp case, 11 tle lanip glass or lens 12{the, concave refl'ectonl3 tl1e guide tube xed axiall at the back of the reflector 12, tlie reflectorheing apertured t0 cor respond' with it; 14 is a sleeve slidable v through tlie guide tube 13 along the axis.of

tlie refi'ector 12. 15 is a socket slidablie in the sleeve 14;. the lamp 16 is fixed in this socket by means of the usual ba-yonet arrangement 17. Tlie sleeve 14: is slotted at* one side,and the socket 151 has a rack 18-. for1iredupon it, the slot accommodating;this rack so that the racl teeth project through thesl'ot. and also tlirough a slot, in the guide tuhe 18". The rack teeth 19 mesh 'ith the teeth 20 of the pinion 21 wliieh is fiXedj on the top end of a flexible shaft 22. 23 is a lug ofi"set from the sleeve 14;. It tapped to carry an adjusting:screw 24: the head 25 of which is exposed at the back of the case- 10'. 26 is a helical= spring in compression. ahutting against the bacls of the case 10 andhea i#ing against the lug 23.. The spring 26 tends te, force tl1e lug 23 and consequently tire sleeve Ir forwardL 'lhe 1forward position is adjusted by rotating the screw. head 25, thereby to bring the filament in the la1np 16 to the focal centre of the refleetor 12.

27 are the lead-in wires of the lamp circuit, 7

CEhe bottom; end, of the shalt 22 carrres a toothed pinion 28 whiel1is honsed between bearing cheeks 29 in the magnet 1rame ass mbl which is mounted in the bottom part of the case 10. 30 and 81 are the electromagnet coils; they are wound in opposed relation so that when either one of. them is encrgized the armature 32" is moved acco'rdingly t0, riglit or lefi7; this armature 32 has a racl'r 33 ont in the. central portion of it, and with. this rack the p inion 28 meshes. On: the opposite side of thearmature 32is a guide andcheck pin 34 which WOkS in a slot in the frame assemhly. 36 is a con.- trol magnet; and: 37 a roclring armature fixlcrnmed on ztpin 38 and carrying a spIit fi'nger 39; this split finger i's spring; plate 4&0 notched as shown at t1 at its lower part with a curved tongue 2' above tlie notch 41; this tongue bears against the frame and normally forces the armature 37 to the free position and clears the tongue 42' so that it will notbe engaged by tlie pin When the control 1nagnet 36 is energized to pull down its armature 37 the split finger is forced inward against. the resistance otr" its tongue 42. When subsequent to its operation one or other of the magnets 30 or 311 is energizedto reverse the position o:f' the armature 32', the check pin 34-. drops into the notch 41 of the split finger and tlie armature is then held at a middle position.

Thus, wlien tlie control magnet 36is unoperated, operation of the: magnet assem b1y 80- and 31 in; either direction lias the e1fct 01 throwing the armature 32" corre spondingly; with the result that the pinion 28, and conseqrntly the shaft 22 and the pinion 21 are rotated. During tire move ment in, one direction tliis rotation has the eifct of n1oviirg*tlie socket 15 to bring tlie lamp 16 to the adjusted focal position which is regtdated by' means ot the screw 241 Movemnt in the reverse direction lies tlie efiect cf slidingtlie socket '15 to niove tlie; lump 16 se that the source of illumi nation will be displaced out of tliefocal centre o:fthe refl*ector: 12, aiul l' range 01- movement efecting total de=fbcussing so tliat a dispersedillumination only ofiering 1'raoticallyno-glare is then ol3tained, Vlien it is judged that a partial de-foenssing; onl'y necessary to convenience other= rond irsers the control magnet is operated t0 limit the stroke of the armature 32 and a-lou the la1np 16 to be moved only suifiCiently i-;

d"estroythe parallelis1h ofthe normal bem.

The diagrammatio view, Fig. 5 shows a convenient arrangement of the amp circuit and contro1s. is a main liglitingsWitch, 456" a reversing switch wrfeli contrels tlie coils 30 and 31, 47 a control switch Which governs the coil 48 of the magnet 36, and 49 is the lighting battery.

It is to be understood that two head lamps 16, instead of one as shoWn, may be used in ordinary parallel arrangement.

WVhen the switch 45 is closed, a circuit through the lamp 16 is established. Wben the switch 46 is thrown to the left hand position another circuit is established through the coi] of the magnet 30, which Will result in movement oi:' the armature 32 to the left. VVhen the switch 46 is thrown to the right hand position, the il et the magnet 31 is similar1y energized and the armature 30 is moved reversely. When the control switch 47 is closed, another circuit is established through the oeil 4-8 of the magnet 36, the, circuit established through the swicch 46 in either direction being simul taneously 0perative.

What We daim as our invention and desire t0 secure by Letters Patent is:

1. An automobile head lamp comprising a concave refiector, a fixed guide iocated axially with the refiect0r focal point, a sleeve within said guide having transverse pinion bearings, means for adjusting and retaining said sleeve axially with respect to the focal point of the refiect0r, a toothed lamp socket slidablewithin said sleeve and adapted to carry a source et light, a pinion engaging the toothed socket, a pinion shaft extending through said pinion and the bearings in said sleeve, a source of light within the focal axis of the reflector, remotely controlled eleotromagnezic means for moving said lamp socket and source of light With respect to the reflector and a checking de vice for a1restingj the movement oli the source of light intermediate its limits of travcl An automobile head lamp comprising concave reflector, a Source of light within the re ector, a device :lor movin said source ol light with respect to the 1'81 ector, com prising a magnet frame, two opposed elec tromagnets mounted in a trame and respectively circuited to a battery and a Control switch, a toothed armature common to both electromagnets and adapted to slide therein, a pinion engaging the toothed armature, a pinion shaft extending through said pinion and the bearings in the magnet frame, a check-pin in said armature, said pin extending through a slot in the magnet frame, a notched spring; plate en aging the Check-pin and a contre] eleotromagnet attached to the magnet rame and operating the notched spring plate and separately circuited to the battery and control switch to arrest the movement of the source of light intermediate its full throw.

3. 1h 1 automobile head lamp comprising a concaved refiector, a fixed guide iocated axially with respect to the refiectcr focal point, a sleeve within said guide having transverse pinion bearings, means for ad justing and retaining said sleeve axially with respect to the reflector focal point, a toothed lamp secket slidab1e within said sleeve and adapted to carry a source of light, a pinion engaging the toothed socket, a pinion shaft extending through said pinion and the bearinggs in said sleeve, a source of light within the focal axis of the refiector, a magnet frame attached to the head iamp and proVided with a transverse pinion bearina" two opposed electromagnets concentrically mounted in said frame and respe& tively circuited to a battery and a control sWiteh, a toothed armature common to both electromagnets and adapted to slide therein, a pinion engaging the toothed armature, a pinion shait extending through said pinion and the bearings in the magnet trame, a flexible couphng connecting both pinion shafts, a check-pin attached to said armature and entending through a s1ot in the magnet frame, a notched spring plate engaging the check-pin, and a contr01 electromagnet attached to the magnet frame and operating the notched spring plate and separately circuiced to the battery and control switch.

4. An automobile l1ad. lamp comprising a refiect0r, a source of light adjustabiy mount ed in the axis of the refieetor, opposed electromagnet coils, a toothed armature movabie by either of said coils, a pinion engaging the teeth of the armature and adapted on the energizing oi either coil to move the source of light with respect to the reflect0r and a distant controlled checkinp; device for arresting the movement of the armature intermediate its throW.

5. An automobile head lamp comprising reflect0r, a source of light adjustably mount ed on the axis et the reflect0r, opposed electromagnet cois, an armature common to both coils, means operated by the armature to move the source of light to and rrom the focal point of: the reflector, and control means for arresting the movement of the armature and to check it at a point intermediate its full throw.

6. An automobile head lamp comprising a refiect0r, a source of light adjustab1y mount ed in the axis of the refleotor, opposed eleetromagnet coils, an armature common to both coils, means operaced by the armature to move the source of light to and from the iocal point of the refiector, and a control magne t for bringing a check into engagement With the armature to arrest its movement at a point intermedate its full throw.

7. An automobile head lamp comprising a refieot0r, a source of light adjustably mounted in the axis of the refiect0r, two elec tromagnet cofls in tandem relation, an artien on the first mentionel armature to armature common to both coils, means operresc its movement and to check t afi; a point ated by the armature to move the source of intermediate its full throw. 10 1ighc to and from the focal point of the testmony whereof We have affixed our x refiector, a projection on the armature, a signatures.

contrcl magnet, an armature operble by THOMAS MILTON BRAGG. said control magnet to engage the projec- JOHN FREDERICK;HOWARTH 

